An Information Centric Network (ICN) is a type of network architecture in which the focus is on locating and providing information to users rather than on connecting end hosts that exchange data. One type of ICN is a Content-Oriented Network (CON). In a CON, also referred to as a Content Centric Network (CCN), a content router is responsible for routing user requests and content to proper recipients. The entities may comprise data content, such as video clips or web pages, and/or infrastructure elements, such as routers, switches, or servers.
Content Delivery Networks (CDNs) have previously been adopted to achieve content delivery. CDNs are typically deployed and operated either (a) independently by third-party CDN carriers as inter-domain overlays spanning across multiple underlying networks operated by multiple Internet Service Providers (ISPs); or (b) by an individual ISP within the ISP's networks in order to achieve intra-domain content dissemination. In the third-party CDN case, these two capabilities may be provisioned by ISPs in an underlay and CDN carrier in an overlay; in ISP-owned CDNs, in-network storage may be managed as an overlay service for the convenience of operations and management.
CONs may differ from CDNs in that the former require that routing and in-network storage capabilities be provisioned jointly and consistently, while the latter may provision them separately and inconsistently. The separation of routing and in-network storage capabilities may lead to potential conflicts. For example, when content storage operates as an overlay service, overlay may cancel off the Traffic Engineering (TE) efforts in the underlay or vice versa. Furthermore, the operational objectives of routing and storage may differ, and recent studies on Internet Protocol (IP) networks indicate that the conflicts may result in significant efficiency loss.
Many ISPs have adopted TE to provision network capabilities. However, TE faces new challenges in CONs, e.g., the conventional flow conservation laws, which are fundamental to all TE algorithms and systems, may no longer hold. This may raise at least three distinct challenges. The first challenge raised is provisioning both routing and storage capabilities simultaneously and consistently. In CONs, each ISP may own and may manage both routing and storage capabilities in its intra-domain network. Existing studies for IP networks suggest that conflicts and efficiency losses could occur if they are provisioned separately. Hence, it may be desirable to align the objectives of provisioning routing and provisioning storage capabilities in CONs and coordinate their practice in order to contain potential conflicts, prevent efficiency losses, and maximize the benefits of CONs. The second challenge arises from the disappearance of the conventional flow conservation laws due to the introduction of CON router storage capabilities. More specifically, the total traffic of outgoing flows of a router may be larger than that of incoming flows, since CONS allow routers to store incoming flows for immediate and later use. As a result, traditional TE algorithms, which all rely on the conventional flow conservation law, may no longer be suitable for CONs. The third challenge that may arise is the relative unpopularity of a dominant portion of the content. A need arises to formulate TE for CONs to optimally provision the CON routers' routing and storage capabilities and help reduce or eliminate such instances.